【作者】 刘聪；

【导师】 史家顺；

【作者基本信息】 东北大学 ， 机械工程（专业学位）， 2019， 硕士

【摘要】 光学曲面超声抛光是近年来新兴的一种抛光技术,这一技术利用高频超声振动使纳米悬浮液中的磨粒与工件表面发生碰撞,达到材料去除的效果,是光学曲面元件抛光的理想工艺。因此,对光学曲面超声抛光机床进行关键技术的研究成为重要课题,根据超声抛光机床五轴运动及变压力控制的要求,本文的主要研究工作如下:(1)分析了光学曲面超声抛光机床的控制特点和要求,对其控制系统进行了总体设计和规划。提出基于PC+UMAC多轴运动控制器的机床上下位开放式控制体系,据此分别对主要硬件体系及上位软件体系进行了设计和规划。(2)探究了光学曲面超声抛光机床数控程序在开放式数控系统中解释和开发的过程及方法。利用现有开放式数控系统构建了带有压力控制指令的G代码数控程序,使抛光的压力控制要求可随五轴运动数控程序发送并被数控系统识别和处理,这一方法可用于抛光机床实际数控程序的解释和开发。(3)分析了光学曲面抛光压力模型,提出了基于高速开关阀的气动抛光压力加载方法,对气动压力加载系统进行了设计、搭建及数学建模,并通过系统离线辨识的方式得到了气动压力加载系统的控制模型。(4)实现了数控系统与气动压力加载系统的结合,对压力加载系统的控制部分进行了软硬件设计及实现,包括数控系统与压力加载系统的通讯、数据传输、电气设计等,在PLC中设计并编写了 PID控制程序用于系统的调节,在MATLAB中对系统进行了仿真分析,仿真验证了 PID控制器能够较好的调节系统的动态特性。(5)进行了不同运动轨迹下的压力加载控制实验。通过对采集的数据进行分析,证明此系统能够有效的对抛光压力进行加载控制,验证了本文提出的随轨迹压力加载控制方案的可行性。通过本文的研究,探索出了一种在开放式数控系统中利用数控程序指令实现抛光压力随轨迹的加载控制方法,达到了预期的研究目的,对今后项目的进一步研究提供了参考和指导。更多还原

【Abstract】 Ultrasonic polishing of optical surface is a new polishing technology in recent years.This technology uses high-frequency ultrasonic vibration to cause the abrasive particles in the nano-suspension to collide with the surface of the workpiece to achieve the effect of material removal.It is an ideal process for polishing optical curved components.Therefore,research and development of the optical curved ultrasonic polishing machine tool has become an important issue.According to the requirements of five-axis motion and variable pressure control of the ultrasonic polishing machine tool,the main work of this thesis is as follows:(1)The control characteristics and requirements of the optical curved ultrasonic polishing machine tool was analyzed and the overall design and planning of its control system were carried out.Based on the PC+UMAC multi-axis motion controller,the upper and lower open control system of the machine tool was proposed.Then,the main hardware system and the upper software system were designed and planned.(2)The process and method of interpretation and development of the NC program of optical curved ultrasonic polishing machine in open CNC system were explored.The G code program with pressure control command was constructed,so that the pressure control requirements of the polishing can be sent with the five-axis motion NC program and recognized by the CNC system.This method can be used for the interpretation and development of CNC programs for the polishing machine.(3)A pneumatic polishing pressure loading method based on high-speed on-off valve was proposed by analyzing the polishing pressure model of optical curved surface.Then,the design,construction and mathematical modeling of the pneumatic pressure loading system were carried out.The control model of the pneumatic pressure loading system was obtained by offline identification.(4)The combination of numerical control system and pneumatic pressure loading system was realized.The communication,data transmission and electrical wiring between the numerical control system and the pressure loading system were carried out.Then,the PID control program was designed and programmed for system adjustment.The system was simulated and analyzed in MATLAB which verified that the PID controller can better adjust the dynamic characteristics of the system.(5)The pressure loading control experiments under different motion trajectories were carried out.The collected data proved that the system can effectively control the polishing pressure,which verified the feasibility of the proposed trajectory pressure loading control scheme.Through the research of this thesis,a method of real-time control of polishing pressure using NC program instructions in open CNC system was explored,which provided reference and guidance for further research.更多还原